Method and apparatus for matching colours

ABSTRACT

A portable color sampling device ( 10 ) facilitates comparison of a color sampled from an object using an optical sensor ( 11 ) with a database ( 30,42,43,44 ) of stored colors. The database ( 30,42,43,44 ) of stored colors includes a merchandise database of articles for sale, and an indication of the location of those articles, including an indication of some or all of retailer identity, store location, in-store location, article description or product ID, class of article and the like. A user points the color sampling device at an article to be sampled, and a color definition data file is generated for transmission to a database of articles. The database returns to the sampling device a list of merchandise that matches the sampled color or colors and any other matching criteria such as class of article, product code, and geographic proximity.

The present invention relates to colour sampling devices, and inparticular to methods and apparatus for matching sampled colour datawith databases containing colour data.

There are many occasions in which it is desirable for a person to beable to accurately match colours of objects. This can be quite difficultto achieve by eye, particularly where the objects to be matched havedifferent textures or materials, or where lighting levels areinconsistent. Often, the matching has to be achieved from memory,without simultaneous direct visual contact with the two items to bematched, which many people find difficult.

For example, it is a common requirement when purchasing home furnishings(including furniture, carpets, curtains, wallpaper, paint and the like)to try to match the colours of those home furnishings with existingcolour schemes in a room in which they will be placed. Typically, thiscan only be accurately achieved by obtaining from the retailer a coloursample (such as a swatch, fabric cutting or match pot of paint, forexample) and taking this colour sample home, prior to deciding on thepurchase.

In another example, it is a common requirement when purchasing clothingfor a person to find articles that match or complement existing items intheir wardrobe, or that match the person's “ideal colours”, as oftenspecified by a style consultant. For example, many people make use of apersonal colour bureau that generates a custom palette of colours suitedto an individual's hair, eye and/or skin colours. Searching for theappropriate clothing items can be time consuming, requiring visits tomany clothing retailers in order to find appropriate items.

Many colour sampling devices are known in the art. For example, U.S.Pat. No. 6,157,454 describes a calorimeter for measurement of the colourof an object. The calorimeter comprises a pen-shaped probe with a probetip, which measures reflectance of the object at the wavelength of thethree primary colours to then determine a colour value by reference to alook-up table of stored reflectance ratios.

U.S. Pat. Nos. 6,043,893 and 5,483,339 both describe portablereflectance spectrophotometers for determining levels of each spectralcomponent of an object. US '339 also proposes an interface to a computerfor transferring a set of colour standards to the spectrophotometer andfor transferring measurement data from the spectrophotometer.

U.S. Pat. No. 5,995,650 describes a portable system for measuring shape,contour, colour and other data relating to an object by rapid scanningof the object with a geometric light shape.

US 2001/44801 describes a system for producing an electronic colourinformation data file for communication of colour data describing one ormore colour samples to a receiver, such that the receiver can displaythe colour. In particular, the system may incorporate in the data filenot only colourimetric data, but also specify colour exchange format,device dependent colour data, surface condition and graininess of theobject and the like.

It is an object of the present invention to provide a portable devicefor locating items having a predetermined colour or colours. It is afurther object of the present invention to provide a portable devicethat is able to sample colours from the environment and then access asearch engine for locating details of products or articles that meetcolour matching requirements.

It is a further object of the present invention to provide a portabledevice that is able to sample colours from the environment and thendetermine a quantitative degree of matching with a colour palette storedtherein.

According to one aspect, the present invention provides a method ofcolour matching comprising the steps of:

sensing colour information representative of an article being sampled,with a portable user device having an optical sensor;

generating a colour definition data file from said colour information;

transmitting said colour definition data file to a remote database;

searching the database for data items that match colour criteriaindicated by the transmitted colour definition data;

generating a list of said data items; and

transmitting said list of data items to the user device.

Optionally, the sensing step includes directing a digital camera to atleast a portion of the article to form an image thereof and defining atarget region of the image for which target region the colourinformation is to be sampled. In this case the method may furtherinclude the step of determining an average of the sensed colourinformation or a representative colour set, for use in generating thecolour definition data file.

Optionally, the sensing step further includes determining a temperatureof the light illuminating the colour image. In this case, the step ofgenerating a colour definition data file can also include incorporatingtemperature of the light illuminating the image that produced the colourdefinition data file.

The method may also include the step of storing a plurality of saidcolour definition data files relating to different articles for latertransmission to the remote database.

The article being sampled may be, for example, any one of an article ofclothing, an article of furniture, a colour sample chart or swatch, afabric, a carpet, curtain material, wallpaper or paint.

The method can further include the step of displaying, on the portableuser device, the list of data items.

Optionally, each data item includes data identifying an articleavailable for purchase. Optionally, each data item may also include dataidentifying a location of the article available for purchase.

The method may further include the step of transmitting an indication oflocation of the user device to the remote database.

The method may further include the step of transmitting, with the colourdefinition data file, an indication of a class of articles to which thecolour defined in the definition file is to be matched.

The method may further include the step of transmitting, with the colourdefinition data file, an indication of a category of article to whichthe colour defined in the definition file is to be matched.

Optionally, the remote database is installed in a retail store, and thestep of generating a list of data items comprises generating a list ofarticles available for sale in the retail store that match colourcriteria indicated by the transmitted colour definition data.

According to another aspect, the present invention provides a method ofcolour matching comprising the steps of:

sensing colour information representative of an article being sampled,with a portable user device having an optical sensor;

generating a colour definition data file from said colour information;

transmitting said colour definition data file to a remote database;

receiving from the remote database a list of one or more data items eachrelating to an article that matches colour criteria indicated by thetransmitted colour definition data; and

providing as output to a user the one or more data items in the list onthe portable user device.

The method may further include the steps of:

receiving product location information with each of the received dataitems; and

providing as output said product location information on the portableuser device.

According to another aspect, the present invention provides a method ofcolour matching comprising the steps of:

receiving a colour definition data file, including colour informationrepresentative of a sampled article, from a portable user device;

searching a database for data items that match colour criteria indicatedby the transmitted colour definition data;

generating a list of one or more data items each relating to an articlethat matches colour criteria indicated by the received colour definitiondata file; and

transmitting said list of data items to the user device.

The method may further include the step of transmitting, to the userdevice, product location information in respect of data items in thelist.

According to another aspect, the present invention provides a method ofcolour matching using a portable colour matching device, comprising thesteps of:

sensing colour information representative of the colour of an articlebeing sampled with an optical sensor;

generating a colour definition data file from said colour information;

storing a plurality of colour definition data files relating topreviously sampled objects;

receiving a colour definition data file relating to a current sampledarticle, and searching colour definition data files in the memory todetermine if any of the stored files match colour criteria indicated bythe colour definition data for a current sample; and

providing as output on the colour matching device an indication if anystored files match the colour criteria.

According to another aspect, the present invention provides a portablecolour sampling device comprising: an optical sensor for sensing colourinformation representative of the colour of an article being sampled;

means for generating a colour definition data file from said colourinformation;

a wireless transmitter for transmitting said colour definition data fileto a remote database; and

a wireless receiver for receiving, from said remote database, a list ofdata items that match colour criteria indicated by the transmittedcolour definition data.

The optical sensor may comprise a digital camera.

In this case the camera may include a visual targeting device enablingthe user to determine a portion of an image of an article for which thecolour information will be generated. The sampling device may furtherinclude means for determining an average of the sensed colourinformation or a representative colour a representative colour set, forincorporation into the colour definition data file.

The optical sensor may further include means for determining thetemperature of the light used to illuminate the colour image. In thiscase the means for determining a temperature of the light illuminatingthe image may include an illumination device.

The device can further include means for reading a product barcode. Thesampling device can further include means for storing a plurality ofsaid colour definition data files for later transmission to a remotedatabase.

The sampling device can further include a display for displaying saidlist of data items.

The sampling device can further include an audio output device forpresenting said list of items to the user.

The transmitter and receiver of the sampling device may comprise amobile telephony device.

The transmitter and receiver of the sampling device may comprise aBluetooth device.

The sampling device may further include means for transmitting, with thecolour definition data file, an indication of current location of thesampling device.

The sampling device may further include means for transmitting, with thecolour definition data file, an indication of a class of articles towhich the colour defined in the definition file should be matched.

According to another aspect of the present invention there may beprovided a personal digital assistant or mobile telephone incorporatingthe sampling device.

According to another aspect, the present invention provides a colourmatching server comprising:

means for receiving, from a portable colour sampling device a colourdefinition data file indicating sensed colour information representativeof the colour of an article;

a database of data items, each data item relating to an article and oneor more colour properties of that article;

a search engine for receiving the colour definition data file andlocating, in the database, data items that match colour criteriaindicated by the transmitted colour definition data;

means for generating a list of said data items; and

means for transmitting said list of data items to the portable coloursampling device.

The means for transmitting and the means for receiving may comprise amobile telephony device.

The means for transmitting and the means for receiving may comprise aBluetooth device.

Each data item may further include data identifying an indication ofretail location of the respective article.

Optionally, the data items relate to articles comprising any one or moreof: an article of clothing, an article of furniture, a colour samplechart or swatch, a fabric, a carpet, curtain material, wallpaper orpaint.

The colour matching server can be installed in a retail store.

According to another aspect, the present invention provides a portablecolour sampling device comprising:

an optical sensor for sensing colour information representative of thecolour of an article being sampled;

means for generating a colour definition data file from said colourinformation;

a memory for storing a plurality of colour definition data filesrelating to previously sampled objects;

a comparison engine for receiving a colour definition data file relatingto a current sampled article, and for searching colour definition datafiles in the memory to determine any of the stored files which matchcolour criteria indicated by the colour definition data for a currentsample; and

means for indicating determined stored files that match the colourcriteria.

The means for indicating may include means for indicating a quantitativedegree of closeness of match to the colour definition data of thecurrent sample.

The means for indicating may comprise a visual display and/or an audiooutput.

Embodiments of the present invention will now be described by way ofexample and with reference to the accompanying drawing in which:

FIG. 1 shows a schematic block diagram of a colour sampling device andnetworked connection to a colour matching server according to thepresent invention.

With reference to FIG. 1, a portable colour sampling device 10 includesan optical sensor 11 adapted to sense colour information representativeof the colour of an article being sampled. Preferably, the opticalsensor 11 is a digital camera, although any form of calorimeter orspectrophotometer device could also be used. The colour sampling device10 further includes a suitable data processing device 12 which generatesa colour definition data file 14 for each article sampled.

The colour definition data file 14 incorporates all the informationnecessary and sufficient to define the colour of the article to arequired degree of accuracy. Many different colour definition protocolsare known in the art—many of these are discussed in US2001/0044801—which may be used in preferred embodiments of the presentinvention. A preferred colour definition protocol uses RGB colour valuesderived from the digital camera 11. The RGB protocol offers a convenient24-bit number representation which is useful for electronic storage andtransmission.

In the preferred embodiment, where the optical sensor 11 is a digitalcamera, the sampling device 10 preferably also includes a viewfinder(not shown) for imaging the surface of the article in view. Theviewfinder may incorporate a visual targeting device, such as across-hair or “box” in the viewfinder which indicates a portion of theimaged article for which colour information will be generated forinclusion into the colour definition data file 14. The colour samplingarea may include a predetermined number of pixels of the imaging device(eg. at least 100) in order to ensure a representative mix of coloursand hues to form an averaged single sample that is properlyrepresentative of the article. For instance it may reduce a colour setto the 8 most common colours.

The processing device 12 may provide an averaging process fordetermining a suitable colour average from colour information receivedin respect of a portion of an imaged article. Thus, an image of anarticle may be captured having a complex array of colours from theportion, and RGB values may be extracted therefrom to produce a range ofcolours that represent the article.

Color quantisation methods known in the art can also be used to reducethe number of colours in the image by producing an optimised set ofrepresentative colours for inclusion into the colour definition datafile. In another embodiment it may be desired to represent a sample setto a single colour. In some instances this could be matched to the nameof a colour or the name of a product colour (eg. a brand-specific paintcolour name). This colour may then be more easily used for databasesearching.

The colour sampling device 10 may include a colour correction system fordetermining the conditions under which the colour data was collected.The processing device 12 may then correct the colour data according to apredefined colour correction standard common to all sampling devices.Alternatively, the processing device 12 may store data identifying theconditions in respect of which correction should be made with the colourdefinition data file. In this way, correction can be performed remotelyfrom the device 10 when colour matching operations are being performed.Thus, the sampling device effectively incorporates means for determiningthe temperature of the light illuminating the sampled article.

In a simplest form, this means for determining temperature of the lightmay be an illumination device provided in the form of a flash unit 13,for which the specific temperature is known, and this temperature may beincorporated into the stored colour definition data files.

The colour sampling device 10 preferably also provides a display device16. This may be a simple, text only display device, or more preferably adisplay having colour graphics capabilities. Where the colour samplingdevice 10 has determined that there are several colours in the object,or portion of the object, being sampled, the display device 16 may beused to display a list or a colour palette of all colours in the sample.The user may then view these colours and decide which should be used togenerate the colour definition data file 14. This may be important wherethe object being samples contains a mix of disparate colours (eg. atweed jacket). The image processing device 12 may determine and displaythe range of colours in the sample, and possibly also resolve the imageto a selection of key colours.

The colour sampling device 10 preferably includes a memory 18 capable ofstoring a number of colour definition data files 19, 20 for future useor reference. These could, for example, correspond to an individualuser's “ideal colour palette” which can be stored by sampling each oneof the specified colours from a printed colour palette.

The colour sampling device 10 further includes a transmitter/receiverdevice 22 (hereinafter “transceiver”) suitable for the transmission ofcolour definition data files through an access point 23 to a remotedatabase 30 over a communication channel 25, and for receiving data fromthe database 30. The transceiver 22 may be any suitable wirelesstransmission system.

In preferred embodiments, the colour sampling device is integrated intoa mobile telephone handset, a personal digital assistant (PDA) or othermobile computing device.

In one arrangement, a short range communication channel 25 may be used,and the transceiver may be a Bluetooth device or the like thatcommunicates with a local server/database 30.

In another arrangement, a longer range mobile telephony transceiver isused over a GSM or GPRS communications channel 26, for example. In thisarrangement, the colour sampling device 10 communicates with a networkgateway device 35 via telephony cell transceiver 32, which forwardscommunications to and from one or more servers 40, 41 over a suitablenetwork 36. The network 36 may be the internet or a suitable wide areanetwork (WAN) or local area network (LAN).

Each one of the networked servers 40, 41 may provide access to one ormore databases 42, 43, 44.

Each of the databases 30, 42 . . . 44 stores information relating to aplurality of data items each having associated colour definition datafor matching against colour criteria derived from or contained in colourdefinition data files 14 transmitted from the colour sampling device 10.Each of the plurality of data items preferably relates to an object orarticle of merchandise available from an associated retail outlet. Theseobjects may be any one of an article of clothing, an article offurniture, a carpet, curtain material, or paint, or any other objecthaving an associated colour.

The database preferably includes, associated with each data item, anindication of the retailer's identity, the store location, and possiblyalso the location of the merchandise within the store. This may beeffected by storing a product code with each data item which can becross-referenced with a retailer's database. Thus, it will be understoodthat the databases 30, 42 . . . 44 may in fact be distributed databases.

A typical mode of use of the system of FIG. 1 will now be described. Auser of the colour sampling device 10 may point the device at an objectwhose colour is to be matched with another object, and initiate a colourcapture process by the optical sensor 11 and data processor 12. Forexample, the user may capture the colours of walls in his or her home,existing furniture or clothing, carpets, curtains and the like, or eachof the colours on his or her personal colour palette. Each of thesecolours is captured and stored in the memory 18 as a colour definitiondata file 19, 20, preferably together with an associated memory tag orlabel identifying the source of the colour.

Preferably, the user is also able to input further data for associationwith the colour definition data file. This further data may identify acategory of article or class of articles to which the data relates,and/or a category of article for which a colour match is desired. Forexample, the user may store colour definition data file 19 with a memorytag indicating that the colour relates to a skirt already owned by theuser. The user may also add data relating to article matching criteria,for example, defining that the user seeks a jacket in a matching colour.

The user may then initiate a transmission of one or more colourdefinition data files, together with the article matching criteria, tothe database 30. Using an appropriate search engine, the databaseprovides, in return, a list of articles that have the requisite colour,and details of the location where they may be found.

The location data may include a retailer ID, a location in a retailstore, or a product code for furnishing to a shop assistant, or a website address and product code for the purposes of on-line shopping.

The data returned from the database 30 may be displayed on the displaydevice 16. According to the bandwidth of the communication channel andcomplexity of the display, the returned data may be a simple textmessage directing the user to a specified shop, together with a suitableproduct code, or may provide a graphical representation of the matchedarticles available, together with retailer address and a map or otherlocation finder.

Alternatively, the database may supply to the user's colour samplingdevice 10 a synthesised voice message providing the necessaryinformation. This is particularly useful where the colour samplingdevice is integrated into a mobile telephone handset.

In another aspect, the colour matching device could be used during ashopping trip to enter the article matching criteria. For example, theuser may find a pair of trousers in the desired style, but fail to findthe colour being sought. The colour definition data file 19 alreadystored in the device 10 may then be transmitted to the database 30together with article matching criteria derived from the (wrongcoloured) article in view. This may be achieved by providing a categoryof article, such as by way of a product barcode. Preferably, the productbarcode could be obtained by way of a barcode reading facility in thecolour sampling device 10. The product barcode will therefore identifythe style required, and the colour definition data will provide thecolour required. It will be recognised that this product barcode readermay be the same optical sensor 11 as used in the colour sampling.

In another example of use, the scope of the database search may beautomatically restricted to a given retailer or department within aretailer by providing a geographical indication of the location of theuser. The geographic location of the user's colour sampling device couldbe provided in a number of ways.

For example, the colour sampling device 10 may be programmed by the userto add data indicating the town or city in which they are shopping, or apostcode region. The device 10 may be provided with an automaticlocation indicator such as by a GPS receiver.

Alternatively, location may be implied through the communicationschannel in use. Where a short range (eg. Bluetooth) communicationschannel 25 is being used, a retail store may provide a number ofBluetooth receivers in each department throughout the store. The colourdefinition data file received from the sampling device 10 may theneffectively include an implied geographical specification for the scopeof the product search, and thereby limit the list of data items thatmatch colour criteria indicated by the transmitted colour definitiondata returned to the sampling device 10.

In an implementation using a mobile telephony communications channel 26,a geographical extent of search may be implied from identification ofthe network cell 32 transceiver that received the transmission. Thedatabase 30, 42 . . . 44 may then be able to restrict the list of dataitems that match colour criteria indicated by the transmitted colourdefinition data to those within a predetermined radius of the locationof the user.

In another embodiment, the colour sampling device may be used in adifferent manner. As described before, the colour sampling device 10includes a memory 18 for storing a number of colour definition datafiles 19, 20 relating to articles sampled by the device. These files mayinclude a users ideal colour palette. In use, a shopper when viewingclothing articles in a store may use the colour sampling device 10 tosimply verify a colour of a clothing article against one or more storedcolour definition files within the device.

Where a sampled colour matches one of the stored colour definition datafiles, the device may display the match, or the nearness of match on thedisplay 16. This assists the user in coordinating colours and providesan electronic mechanism for approving a match. The device may include aprocess for determining an index of merit indicating a closeness ofmatch, or a degree of complement between, a sampled colour and each of aset of stored colour definition data files.

The colour sampling device 10 may be adapted to provide a name to eachsampled colour, which name can be displayed or voice synthesised, to beof assistance to colour blind, blind or partially sighted persons.

Other embodiments are intentionally within the scope of the accompanyingclaims.

1. A method of colour matching comprising the steps of: sensing colourinformation representative of an article being sampled, with a portableuser device having an optical sensor; generating a colour definitiondata file from said colour information; transmitting said colourdefinition data file to a remote database; searching the database fordata items that match colour criteria indicated by the transmittedcolour definition data file; generating a list of said data items; andtransmitting said list of data items to the user device.
 2. The methodof claim 1 in which the sensing step includes directing a digital camerato at least a portion of the article to form an image thereof anddefining a target region of the image for which target region the colourinformation is to be sampled.
 3. The method of claim 2 further includingdetermining an average of the sensed colour information or arepresentative colour set, for use in generating the colour definitiondata file.
 4. The method of claim 1 in which the sensing step furtherincludes determining a temperature of the light illuminating the colourimage.
 5. The method of claim 4 in which the step of generating a colourdefinition data file includes incorporating temperature of the lightilluminating the image that produced the colour definition data file. 6.A method of colour matching comprising the steps of: sensing colourinformation representative of an article being sampled, with a portableuser device having an optical sensor; generating a colour definitiondata file from said colour information; transmitting said colourdefinition data file to a remote database; receiving from the remotedatabase a list of one or more data items, each relating to an articlethat matches colour criteria indicated by the transmitted colourdefinition data file; and providing as output to a user the one or moredata items in the list on the portable user device.
 7. The method ofclaim 6 further including the steps of: receiving product locationinformation with each of the received data items; and providing asoutput said product location information on the portable user device. 8.A method of colour matching comprising the steps of: receiving from aportable user device a colour definition data file including colourinformation representative of a sampled article and an indication ofcurrent location of the portable user device; searching a database fordata items that match colour criteria indicated by the received colourdefinition data file; generating a list of one or more data items eachrelating to an article that matches colour criteria indicated by thereceived colour definition data file; and transmitting said list of dataitems to the user device, wherein each data item includes dataidentifying an indication of retail location of the respective article.9. A method of colour matching using a portable colour matching device,comprising the steps of: sensing colour information representative ofthe colour of an article being sampled with an optical sensor;generating a colour definition data file from said colour information;storing a plurality of colour definition data files relating topreviously sampled objects; receiving a colour definition data filerelating to a current sampled article, and searching colour definitiondata files in the memory to determine if any of the stored files matchonly colour criteria indicated by the colour definition data file for acurrent sample; and providing as output on the colour matching device anindication if any stored files match the colour criteria.
 10. A portablecolour sampling device comprising: an optical sensor for sensing colourinformation representative of the colour of an article being sampled;means for generating a colour definition data file from said colourinformation; a wireless transmitter for transmitting said colourdefinition data file to a remote database; and a wireless receiver forreceiving, from said remote database, a list of data items that matchcolour criteria indicated by the transmitted colour definition datafile.
 11. The sampling device of claim 10 in which the optical sensorfurther includes means for determining the temperature of the light usedto illuminate the colour image.
 12. The sampling device of claim 10further including means for transmitting, with the colour definitiondata file, an indication of current location of the sampling device. 13.A colour matching server comprising: means for receiving, from aportable colour sampling device a colour definition data file indicatingsensed colour information representative of the colour of an article; adatabase of data items, each data item relating to an article and one ormore colour properties of that article; a search engine for receivingthe colour definition data file and locating, in the database, dataitems that match only colour criteria indicated by the received colourdefinition data file; means for generating a list of said data items;and means for transmitting said list of data items to the portablecolour sampling device.
 14. The colour matching server of claim 13 inwhich each data item further includes data identifying an indication ofretail location of the respective article.
 15. A portable coloursampling device comprising: an optical sensor for sensing colourinformation representative of the colour of an article being sampled;means for generating a colour definition data file from said colourinformation; a memory for storing a plurality of colour definition datafiles relating to previously sampled objects; a comparison engine forreceiving a colour definition data file relating to a current sampledarticle, and for searching colour definition data files in the memory todetermine any of the stored files which match colour criteria indicatedby the colour definition data for a current sample; and means forindicating determined stored files that match the colour criteria.